Synthesis and piezoelectric response of cubic and spherical LiNbO3 nanocrystals

Abstract

Methods have been developed for the shape-selective synthesis of ferroelectric LiNbO₃ nanoparticles. Decomposition of the single-source precursor, LiNb(O-Et)₆, in the absence of surfactants, can reproducibly lead to either cube- or sphere-like nanoparticles. X-Ray diffraction shows that the LiNbO₃ nanoparticles are rhombohedral (R3c). Sample properties were examined by piezoresponse force microscopy (PFM) and Raman where both sets of nanoparticles exhibit ferroelectricity. The longitudinal piezoelectric coefficients, d₃₃, varied with shape where the largest value was exhibited in the nanocubes (17 pm V⁻¹ for the cubes versus 12 pm V⁻¹ for spheres).